Future space probes that operate in cooperative swarms must self-sacrifice if they begin to fail and risk damaging their neighbors in the swarm. Swarm-based missions may be the wave of the future, whereby space exploration is undertaken not by one large spacecraft but by swarming formations of much smaller, cheaper ones. Such smaller spacecraft could collectively provide a “floating optics” system for a space telescope comprising, for example, separate spacecraft flying in formation. In such a system, however, if one spacecraft in the swarm begins to fail and risks a calamitous collision with another, it must sense its end is nigh and put itself on a course that takes it forever away from the swarm, for the greater good of the collective. Failing that, perhaps because it has too little fuel to move away, it must “passivate” itself by deactivating all its systems. This would mean discharging its batteries so as to pose no risk of shock in a collision, and venting any last vestiges of fuel that could explode in a crash. Then its neighbors would be programmed to navigate around the lifeless satellite. When certain failure modes are sensed, the craft must self-sacrifice voluntarily by transformation or self-destruction. This is analogous to the way bee colonies operate, with the workers cooperating to ensure that the mission, that is, reproduction by the queen, succeeds at all costs, even at their own peril.
The common goals of much contemporary software development are related to quality, flexibility, security, and exploiting emergent behavior, which imply an inherent need for self-management and self-monitoring. There are many examples of emergent behavior in the insect world. For example, when it gets cold, the worker bees gather around the queen bee to warm her with the heat of their bodies, resulting in some of them freezing to death. In another example, bee stingers are a relatively strong defense mechanism for protecting a hive, but whenever a bee stings, it dies. In yet another example, the soldier termites defend the colony by blocking the tunnels with their body. Usually more soldiers stand by behind the initial soldier so once the first one falls, another soldier will take his place. In the case that the intrusion is coming from a large breach that cannot be blocked by a single soldier, more solder termites form a phalanx-like formation that blocks the entire breach, until the latter is repaired by other termites.
In human beings, the self-destruction behavior of human body cells is considered as an intrinsic safety mechanism of the human body. It seems that the lifetime of a cell is programmed and that cells know when to commit suicide. This self-destruction is an intrinsic property that can be delayed due to the continuous receipt of biochemical reprieves. This process, also known as “death by default”, or apoptosis, prevents cells from dying due to constant receipt of biochemical “stay alive” reprieve signals. Investigations into the apoptosis process have discovered that whenever a cell divides, it commits suicide due to lack of reprieve signals. It is believed that the reason for this is self-protection, as the most dangerous time for the body is when a cell divides, since if just one of the billions of cells locks into division the result is a tumor.
Moreover, metamorphosis and transformation processes are observable in different species. Metamorphosis is a biological process whereby a living organism physically changes its form or structure during development. Perhaps the most notable form of metamorphosis is the transformation from the immature insect into the adult form. Another form of metamorphosis is observed in chameleons, which are famous for their ability to change their skin color to blend in with their surroundings.
Furthermore, there are living organisms called sequential hermaphrodites (or dichogamy) which are organisms born as one sex and which then later change into the other sex. A few species in this group can change gender multiple times, but they can only function as one sex at a time. Unlike humans, the DNA of these species does not determine their gender, allowing full functional gender change without modifying the DNA.
It should be understood that emergence is not about complexity and simplicity, but is more about features that, being not present at a local level, appear at a global level, but whose uncontrolled appearance may result in greater levels of complexity.
Biologically-inspired computing adopts biological approaches to effective problem solving, where solutions developed by nature through millions of years of evolution are applied in the computing milieu.
Sterritt and Hinchey describe self-destruction in agent-based systems as a last resort situation to prevent further damage that can be due to race conditions or undesirable emergent behavior. In their approach, they propose an apoptosis “stay alive” construct used to confirm that if an agent is still within the correct context and behavior it should stay alive and not self-destruct. See, R. Sterritt and M. G. Hinchey, “Apoptosis and Self-Destruct: A Contribution to Autonomic Agents?”, Proc. FAABS-III, 3rd NASA/IEEE Workshop on Formal Approaches to Agent-Based Systems, Greenbelt, M D, Springer Verlag (2005), which is incorporated herein in its entirety by reference.
Hartline describes a premature termination of a mobile agent from a malicious host in order to facilitate security measures. See, J. D. Hartline, Mobile Agents: A Survey of Fault Tolerance and Security. University of Washington, (1998), which is incorporated herein in its entirety by reference.
Chapelle et al. propose an architecture of cooperative agents where, due to a satisfaction model and local signals, agents learn to select behaviors that are well adapted to their neighbor's activities. See, J. Chapelle, O. Simonin, and J. Ferber, “How Situated Agents can Learn to Cooperate by Monitoring their Neighbors' Satisfaction”, In Proc. of the 15th European Conference on Artificial Intelligence, 2002, pp. 68-72, which is incorporated herein in its entirety by reference.
Research into the self-sacrifice behavior of living species is currently being conducted at University of Cambridge, where researchers have developed a computer defense system that mimics how bees sacrifice the elves for the greater good of the hive. In this approach, “suicide nodes” defend networks from within. The idea is to give all the devices on a network, or nodes, the ability to destroy themselves, and take down any nearby malevolent devices with them. The self-sacrifice provision provides a defense against malicious nodes attacking clean nodes. The technique, called “suicide revocation,” allows a single node to decide if a nearby node's behavior is malevolent, and if so, to shut it down, but at the cost of deactivating itself. Often, at the time an autonomous device receives or generates a self-sacrifice or shut-down signal, it still has good, valuable, and relatively nearby resources or assets that would be destroyed during a self-sacrifice operation.